1. Field of the Invention
This invention relates to a picture processing unit which reads picture information on an original and processes said information electrically and to the mechanism for reading.
2. Description of the Prior Art
Until now, in picture recording units, especially in copying units, although the deformation, reversion, and back printing of the entire picture have been performed, the deformation, reversion, and back printing of a partial image on the picture have not been put into practice.
The reason for this is that since in the conventional copying machines the latent image of original picture information is formed on a light sensitive body, etc. through an optical system, a large scale of unit is required. However, there are cases in which insertion of a reduced graph or table into a handmade original, reversion of a part of a drawing or sentences, or back printing of a portion of a drawing or design is desired.
If these operations become possible with a unit having an inexpensive and simple mechanism, it is very convenient. On the other hand, the word processors known at present having a memory capacity greater than the capacity of one page of picture, indicate such information in the memory on CRT screen. The operator makes editorial directions using a light pen or keyboard while watching the CRT picture, and after reassembling the information in the memory according to the directions, sets this in-memory information on the picture recording unit which uses a laser beam, etc. to visualize it. Consider how much capacity is required to store in a digital memory the picture information of A4 size. Assuming 20 bits (picture element 10 lines/mm) per mm, 24M bits are required since A4 size is ##EQU1##
To provide an editorial function a buffer memory having the same or more capacity as 24M bits is required. This makes the entire unit very expensive.